Introduction - new HP15C owner

[Johnh]

Hello, I’m a new member here and I think I’ve arrived, as I took delivery of my HP15C CE yesterday. So far I’m very pleased.

I’m in the last few years (and maybe a few more) of my career as a structural engineer. I teach it and I design structures. HP calculators have been there on my wish list from about as soon as I knew what a calculator could do, pretty much exactly from the HP35, which corresponded to my being at an age of 13.

All through those 50 years, the need to analyse and work the numbers has been there at school, University and on the job. But, I never owned an HP until about 6 years ago, with an HP35s.

My first calculator was a Sinclair Scientific, an amazing achievement in getting some maths functionality out of a platform designed for making a basic calculator. Fun to play with, but not accurate enough even for high-school, which started to allow calculators in place of sliderules a couple of years later. But I’m glad I had it because it taught me to appreciate RPN, and what you learn at that age is easily learnt!

The later programable calcs brought a very personal connection to the analysis, in a way that the computers of the 70’s and 80’s and into the 90’s couldn’t match because they were too rare, expensive, big and generally clunky. My friend had a HP25C, and I wanted it…

But every time, when I needed to consider a new device for myself, the HP’s were beautiful and wonderfully made, but for a given $, ‘lesser’ models from TI or Casio would always do more. I had a TI58 at University, and Casio programmable and pocket computers with lots of memory that ran BASIC; very handy in the 1980’s. And there would usually be a better one in a couple of years anyway. None of them work now!

These days that need for personal connection and programming is met generally by laptops and spreadsheets, together with proprietary software with full network backup and QA.

But I still feel the need to punch numbers, maybe ad-hoc, ‘back-of-the-envelope’ calcs to help think about something, or do a sanity check on the latest mega ETABS analysis. And that’s where the HP’s have finally become perfect for me! They feel reliable, I can see them clearly (especially the new 15C) and they are handy. A good range of functions and access to simple programming make them very useful tools for the technical leader in engineering. And the buttons work and feel right when you press them at speed, unlike those old Casios!

I’ve liked my HP35s, it’s a proper RPN HP and generally reliable in use and plenty powerful. What I don’t love about it is that every couple of years despite great care, and for various reasons, something happens to cause it to lose everything. With its substantial power and memory, its tempting to put a lot into it, but in practice its more volatile than it should be and there’s only fingers for putting it all back in.

So I think from now on, Ill just work with the simplest and most useful program routines that I have, and I'll adapt them also for the HP15C, which compared to the 35s, is that bit nicer and clearer and the buttons are even more positive.

thanks for reading!
John (NSW Australia)

[EdS2]

Nice intro - welcome!

[johnb]

Welcome aboard, John.H!

I think you will fit in nicely here!

Your story parallels that of mine and of many others here. I'm a little younger (age 10 when the HP-35 was released) but I too remember drooling over friends' HP's: the 45, 25, 67, and so forth. And for me too those prices were mostly out of reach (or later in the 1980s, not justifiable to my new wife).

Then one day I accidentally tripped across an HP-28s in a yard sale for about $2, in beautiful condition. (I remembered being awestruck when it first came out: symbolics, on a calculator!) I grabbed it and I was hooked.

So [don't] be careful: its an addiction. Fortunately a wholesome and harmless one.

BTW, I, too, had the Sinclair Scientific! Very pretty little thing, but as you said, not really up to the task. LOL... did you have several programs memorized where you could just key them in rapidly from memory? I did! [Ed. for others: the machine did not have continuous memory. And very little space for vars and program, for that matter.]


So, again, whether you own 2 HP's, or 20, or 200, you'll be welcomed with open arms here; we're glad to have you!

[johnb]

(10-05-2023 01:42 AM)Johnh Wrote:  I’ve liked my HP35s, it’s a proper RPN HP and generally reliable in use and plenty powerful. What I don’t love about it is that every couple of years despite great care, and for various reasons, something happens to cause it to lose everything. With its substantial power and memory, its tempting to put a lot into it, but in practice its more volatile than it should be and there’s only fingers for putting it all back in.

So I think from now on, Ill just work with the simplest and most useful program routines that I have, and I'll adapt them also for the HP15C, which compared to the 35s, is that bit nicer and clearer and the buttons are even more positive.

Fortunately, the HP-15c/CE is reasonably hackable to add a USB port to it. There's also the WP-34s and WP-31s that you can create by flashing the firmware of an HP-30b (business model; off the market now but still generally cheaply available AFAICR). Those can be fairly reasonably hacked to have a USB port as well. (If you don't want to do it yourself, there are members of the collectors' community who will do it for you, for a fee.)

Or... you can keep your eye out for something at a reasonable price in the 48/49/50 series, which have the ports already built in. Not nearly as portable, in exchange for having a turnkey means of backup/restore.

Finally, there are the DM series of very solidly built HP-workalikes, at https://www.swissmicros.com/ Most of those come with a built in port.

Hope this helps!

[BobVA]

Welcome aboard!

Do check out the SwissMicro DM-42 - it's become my daily driver. Traditional RPN programmable with a lot of useful functions and easy backup to both internal storage or a PC.

[Johnh]

Thanks for the warm welcomes and interesting comments!

That Sinclair Scientific that I first had was the non-programmable version. Definitely an interesting point in history, but hopefully not one that got used for much mission-critical engineering. I remember it took about 15 seconds to work out a Sine function, to an accuracy that was about the same as I could guess.

With the HP's, it's fascinating to find out that these devices are not frozen in time, but get hacked, adapted, emulated and reimagined to bring them into the present. I have a nice collection of Android versions. Touch 15i seems like the best HP15c app, and Free42, (with a smoother skin) is great too. For a basic algebraic calc app, I like Panecal Plus and it's worth a few $ for the paid version.

i have one more actual HP. It came free the other day with the HP15c CE and it's an HP39gII. Old new stock, with old batteries but that's no problem. I'm not sure what to make of this yet, it seems like a good high-school quality, with graphics and USB. But it's complicated looking, a big clunky thing with really small fonts. Helpfully, it came with a printed manual, in Chinese!, and more manuals, on CD!. No doubt I can download one though. I don't think it'll get much use from me, but is it worth investigating further to understand it?

[carey]

(10-05-2023 08:47 PM)Johnh Wrote:  I don't think it'll [HP39gii] get much use from me, but is it worth investigating further to understand it?

A few strengths of the HP39gii (and HP Prime) are:
1) An adaptive plotting algorithm that plots more points where functions change rapidly, resulting in more accurate and higher-resolution plots.
2) A structured programming language with similarities to Modula-2 (another Wirth language that evolved from Pascal). Functions can be defined that behave as 1st class objects (i.e., as if built-in) though slower.
3) Similar UI and functionality as the older 38/39 series (38g, 39g, 39g+, 39gs), an advantage, of course, if already familiar with these models or if the idea of Applets (mathematical environments with integrated numeric, symbolic, and plotting capabilities for doing and exploring math) is attractive.
4) Speedy operation. The 38gii clock speed (around 80 MHZ) is similar to the 39gs, however, the latter emulates a Saturn processor, while the 38gii runs without an emulation speed penalty on a platform-independent C codebase.
5) Unicode characters and improved unit capabilities.

Alas, before the many programmer months and additional ROM update cycles that would have been needed for a more stable 39gii, the particular Freescale chip it used went out of production. While still quite a usable calculator, freezing and resetting are not rare, which gives the calculator the feel of a work-in-progress, even after its last ROM update. This is not surprising considering that the 39gii required writing platform-independent C code from scratch rather than emulating previous HP calculator processors. I recall seeing several useful MoHPC posts that offer various key combinations to try in cases of freezing.

[dmh]

Welcome, John, from another Australian (Melbourne)!

I wonder how many there are of us on here now.

Regards, Darren

[kmidson]

(10-06-2023 06:12 AM)dmh Wrote:  Welcome, John, from another Australian (Melbourne)!

I wonder how many there are of us on here now.

Regards, Darren

From Australia you mean? Greetings from Tasmania!

https://www.flickr.com/photos/keithmidso...6354812528

[Eddie W. Shore]

Welcome, John! Glad to have you.

The new HP 15CE CE, I am impressed with increased memory, speed, along with the matrix capabilities.

[kmidson]

Funny I haven't been active on this forum for a few years. I stumbled across the 15C-CE and thought i'd misread "Collectors Edition" instead of the "Limited Edition" version that came out in 2011. So after a brief moment of disbelief, I did a quick search and have now ordered one! I'm sure i'll upload some photos to the collection when it arrives.